Slot-Die Coating 30 nm Thick Perovskite Films for Large-Area Red Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Chemical Engineering

Background:

• Metal halide perovskite light-emitting diodes (LEDs) offer excellent color purity and efficiency.
• Current high-performance perovskite LEDs are typically small-area devices made by spin-coating.
• Scalable fabrication methods like slot-die coating face challenges with perovskite film uniformity on hydrophobic substrates.

Purpose of the Study:

• To address the limitations of slot-die coating for perovskite film formation.
• To develop a strategy for uniform, thin perovskite films suitable for large-area LEDs.
• To enable scalable manufacturing of high-performance perovskite optoelectronic devices.

Main Methods:

• Additive engineering of perovskite precursor solutions with polar additives.
• Introduction of additives to enhance substrate wettability and accelerate nucleation.
• Utilizing slot-die coating for uniform perovskite film deposition.

Main Results:

• Achieved uniform perovskite films with 1.86 nm roughness across 100 cm², at a thickness of 30 nm.
• Demonstrated slot-die-coated red perovskite LEDs with external quantum efficiency over 21%.
• Showcased uniform electroluminescence from large-area devices (80 cm²).

Conclusions:

• Additive engineering effectively overcomes wettability and nucleation issues in slot-die coating of perovskites.
• The developed method enables scalable fabrication of high-performance, large-area perovskite LEDs.
• This strategy is promising for advancing perovskite optoelectronics manufacturing.